Beating yourself up doesn't help you, let alone anyone else.
And when your "monkey mind" is trying to criticise you, remember that one's mind is called "your mind" and not "you". If you are finding you are spending a lot of time playing games that don't result in a win, why not take a break, save the game and do something else that you enjoy while being "in" the moment? When in self-criticism mode you are focusing on the past or the future but the present is the "gift", right now. Even if you don't believe in anything else, you can't effect/affect anything if you are focusing on something other than the present moment and the opportunities it offers.
When in a dangerous game situation, write a few notes (on paper if this is not available in game) then save the game and come back later.
Regardless of anything else, here now on Earth, time and energy is limited relative to possible choices, so it is always better to do something enjoyable than to make a snap decision in a turn-based game if you have "lost" games that way in the past.
I'm enjoying Hellcrawl at the moment.
It has a casual mode that is a lot easier, and this DCSS fork is a lot more focused on the current level since there are no upstairs. Also, I know there are no hatch traps, and AFAIK no unavoidable traps at all in Hellcrawl.
Best regards,
Steven.